As an example of accessories, ready-made pearl necklaces are available in four types of length: choker (about 35 cm), princess (about 40–43 cm) matinee (about 53 cm), and opera (71 cm). The choker, which is the shortest among the four types of necklaces, rests most closely around the neck, and the princess, the matinee and the opera fall from the neck more deeply in the order mentioned. Naturally, the degree of fall depends on wearer's physique and her clothes of the day. Accordingly, a wearer selects a necklace of suitable length which is proportionate to her physique and which matches the clothes to be worn with the necklace. However, because pearl necklaces are generally expensive, it is not easy to own all types of necklaces mentioned above. Hence, in reality, a wearer is not free to make such selection. This reality can be overcome if the loop size of a necklace is freely adjustable. Nevertheless, a necklace is usually equipped with a pair of clasps on both ends and put on the body by engaging the clasps together. Such a necklace cannot adjust its loop size.
To solve this problem, various suggestions have been made for necklaces which can freely adjust their loop size. For example, as disclosed in Japanese Patent Laid-open Publication No. S60-207606, Japanese Patent Laid-open Publication No. S60-207607, and Japanese Utility Model Publication No. S48-41600, one end of a necklace is equipped with a clasp which is capable of pinching a spherical body of the necklace. The loop size of this necklace can be freely adjusted by allowing the clasp to pinch any optional spherical body at the other end of the necklace. To give further examples, as disclosed in Japanese Utility Model Registration No. 3041020 and Japanese Utility Model Registration No. 3060035, one end of a necklace is equipped with a clasp which is capable of hanging on a thread which strings multiple spherical bodies. The loop size of this necklace can be freely adjusted by allowing the clasp to hang on the string at any optional position on the other end of the necklace. In addition, Japanese Utility Model Laid-open Publication No. S52-124894 discloses a necklace which combines these two manners.
However, these conventional necklaces have the following problems. In the case where a clasp provided at one end of a necklace is arranged to pinch any optional spherical body at the other end of the necklace, the clasp is likely to mar the spherical body, spoiling the value of the necklace. For a pearl necklace, in particular, generation of flaws is critical.
As for the case where a clasp provided at one end of a necklace is arranged to hang on the string at any optional position on the other end of the necklace, the clasp damages the string every time the necklace is put on and off. In the course of repeated use, the string may finally break. Particularly, the string used in a pearl necklace, which is generally a silk thread or the like, is more likely to break. Breakage of a thread is a serious problem, considering a higher durability is demanded for a more valuable necklace.
Inevitably, the necklace combining these two manners experiences the problems of the both.
Besides, the clasps employed in all of the above necklaces have extremely complex structures. Hence, the necklaces not only increase the cost for the clasps but also complicate the procedures for putting on and removing the necklaces. In this respect, it should be particularly understood that a wearer has to put on and off the necklace around the neck where her view is very limited. Under such circumstances, complicated wearing and removing procedures are critical disadvantages for necklaces. What is worse, an aged or disabled person finds it more difficult to put on and off such necklaces.
Additionally, the clasps in all of these necklaces are apparently visible while the necklace is worn, so that others can notice that the loop size is adjusted. Thus, these necklaces have to sacrifice the overall design.
The present invention is made in order to solve the conventional problems as above. An object of the invention is to provide an accessory whose loop size is freely adjustable and which protects gems from being damaged by a clasp.
Another object of the present invention is to provide a highly durable accessory which protects a thread from being damaged by a clasp in the process where the accessory is put on and off, so that the thread is unlikely to break for a long period.
Yet another object of the present invention is to provide an accessory which can be put on and off by remarkably easy procedures, so that an aged or disabled person can put it on and off easily.
Still another object of the present invention is to provide an accessory in which a hook at the joint of the loop is totally invisible while the necklace is worn, so that others may less likely to notice that the loop size is adjusted.